Conventionally, various types of electronic apparatus have been developed and become widespread. As an example of such devices, personal computers (hereinafter refer to as “PC”) having a data processing function will be described here.
In addition to desktop PCs, notebook PCs are widely used as PCs. The desktop PCs are each composed of: a main unit performing data processing, which is equipped with a CPU, a hard disk, etc.; an image display unit having a screen for displaying images; and a keyboard used for key operation, which are disposed in separate respective housings. The notebook PCs are portable and each composed of: an image display unit having a display screen; and a main unit having a CPU performing data processing, a hard disk for storing information, and the like incorporated therein, and having arrayed keys on the top to serve also as a keyboard. The image display unit and the main unit of the notebook PCs are connected via hinges.
The notebook PCs can be folded in two by superposing the image display unit and the main unit via hinges and thus it is convenient to carry. In addition, the notebook PCs can be unfolded by making the image display unit and the main unit open with respect to each other so that a user can operate keys while looking at the display screen, and thus it has excellent operability.
Because importance is placed on portability and thin structure in a folded state, the performance of the notebook PCs is considerably sacrificed in terms of functions compared to the desktop PCs. In addition, since the notebook PCs are usually used like a desktop PC in many cases, i.e. they are placed on a desk and used without being carried, recent years have seen the emergence of integral-type PCs having full functions and portability to some extent although the portability is not as high as that of notebook PCs. Typically, the integral-type PCs are each composed of: a base section to be placed on a flat surface like the top of a desk; a standing section standing on and supported by the base section and having a display screen; and a keyboard connected to the standing section via hinges and openable and closable with respect to the standing section. In the integral-type PCs, when not in use, the keyboard can be made stood against the standing section in such a manner as to be superposed on the standing section so that space on the desk can be obtained. In addition, the integral-type PCs are easy to carry because they are integrally configured.
Many of such notebook PCs and integral-type PCs have hinges as described above, and it is ensured that these computers are housed in a compact manner when not in use and that they are convenient to carry (refer to Patent Documents 1 and 2, for example).
In the notebook PCs, components heavy in weight such as hard disk, CD drive, etc. are disposed in a main unit having a keyboard on the top. Also, the notebook PCs are so configured as to have a heavy battery pack loaded in the main unit because importance is placed on portability (refer to Patent Document 3, for example). Loading a battery pack enables the notebook PCs to operate for a while as long as power remains in the battery even when AC power is not available.
In contrast, although the integral-type PCs may also be so configured as to have a battery pack loaded therein like the notebook PCs to improve its portability, this is not preferable for the following reason. In the integral-type PCs, if a battery pack is loaded in its housing having the keyboard like the notebook PCs, the keyboard that is folded to stand against the standing section becomes heavy in weight, which leads to a situation where it is difficult to perform open/close motions and to keep the PC stable in a closed position. There has been devised and proposed a notebook PC whose central position does not shift even if it is opened and closed (refer to Patent Document 4, for example). However, the proposed notebook PC requires a special mechanism, therefore resulting in complicated mechanisms, which is contrary to the demand for packing of functions, downsizing, and weight reduction.
(Patent Document 1)
Japanese Patent Application Publication No. 10-11189
(Patent Document 2)
Japanese Patent Application Publication No. 11-212665
(Patent Document 3)
Japanese Patent Application Publication No. 4-123213
(Patent Document 4)
Japanese Patent Application Publication No. 10-133772
In view of the above circumstances, an object of the present invention is to provide an electronic apparatus such as an integral-type PC whose weight is appropriately distributed.